Multichamber container for blood or other fluid samples

ABSTRACT

A device for taking fluid samples, comprising sample chambers which are separable after filling, have self sealing closures and are so disposed that a needle can fill them successively without withdrawal from an initially pierced closure that separates the chambers, or the first of them from the exterior.

This is a submission under 35 U.S.C. 371 of PCT GB93/02018.

AREA OF THE INVENTION

Much of what follows refers specifically to the collection of samples ofvenous or arterial blood for the performance of chemical, biochemical,biological or physical tests; as is often required in the practice ofmedicine for diagnosis of disease, control of treatment, or monitoringof progress. The principles of the invention are however applicable morewidely, to the collection of other fluids whether or pathological orbiological nature, or otherwise.

PROBLEMS

The procedures and equipment used at present for taking blood samplesremain imperfect, with many problems. Those particularly addressed bythe present invention are as follows:

i) It is frequently necessary to take several samples of blood from onepatient at one time for different tests. To avoid undue distress to thepatient from multiple skin punctures, but also because for somediagnostic and analytical purposes it is desirable that all thedifferent samples are known to come from a single site at exactly thesame time, blood is drawn from the blood vessel through a needle or anin-dwelling catheter and distributed between several pre-preparedcontainers, with or without the intervention of a syringe to serve as aprimary but temporary extracorporeal receptacle. The eventual containersdiffer most often in respect of the additives placed within them toprevent coagulation (according to the test to be done), or to encouragecoagulation, or to facilitate separation of cells from the fluid portionof blood, etc. But they may differ also in size, and even if containingthe same additives, separate containers may be required for despatch todifferent analysts.

ii) In nearly every case the blood must be distributed immediatelybetween eventual containers, adjacent to and within view of the patient.This is anyway a tense situation, made more so by the manipulativedifficulties. Tension is communicated to the patient, with adverseeffects which are greater because he (or she) is anyway concerned aboutlosing even a little blood, is usually upset by the mere sight of blood,and more so if it is spilled.

iii) After any blood-sampling operation, traces of blood are inevitablyfound on the cotton swabs which are invariably used, or the outside ofthe container, needle or other apparatus. But in a multiple-samplingoperation such spillage is much more extensive. Any such contact betweenthe sampled blood and the environment is undesirable for two distancereasons--the blood itself may be altered so that the test result isincorrect or misleading, and there is a health hazard from bloodcontacting other people (e.g. AIDS infection of health-care personnel).

iv) The containers for blood for analysis must be labelled to show thatthey come from the patient concerned, and at what date and time. Whetheror not a system of pre-labelling is used, the conditions of blood-takingare such that confusion of labelling is frequent. The laboratory orother personnel carrying out the tests have usually no direct means ofdetecting that an error has occurred, so that the result reportedappears to refer to the patient and/or sampling time concerned but infact is based on analysis of a sample from a quite different person or adifferent time. Commonly two samples are interchanged, so that resultson two patients or two sampling times are affected. The consequences ofthis type of error can be serious, even fatal, and moreover, if thecause is not detected, there may be loss of confidence in test resultsfor the future.

When an indwelling catheter is used, it must be filled with a solutionto prevent coagulation, and in any case is commonly used for infusion offluids. Thus, when a blood sample is to be drawn from an indwellingcatheter, the first portion of fluid flowing from the catheter is notblood at all, or not a representative sample, and must not be used foranalysis. To a lesser degree, the first portion of any sample of blooddrawn via conventional venous or arterial puncture should be viewed asnon-representative. Whether the matter is sufficiently serious to demandaction varies according to the tests required.

A point of great importance in sampling blood is that a sampling needleshould never be exposed to a non-evacuated space while it is incommunication with the source of the sample. Samples are commonly ofvenous blood, where the pressure within the blood vessel can easily benegative relative to atmosphere (e.g. in a raised arm, as blood drainsto the heart). A needle exposed to atmosphere in such circumstances candraw air, with disastrous consequences for the patient.

vii) Ease of manipulative procedure is of positive benefit to health asdiscussed under (ii) and (iii) above. But medical services must bedelivered at low cost if they are to be available to the wholepopulation. Also, equipment for taking or handling blood shouldpreferably not be re-used, for reasons analogous to those under (iii).Thus sample containers should be constructed of such materials, and ofsuch a simple design as to be inexpensive and disposable, as well asbeing easy in use.

PRIOR ART

The problems discussed above are well recognised, and numerous designsand patents exist which address one or more of them.

1a) Self-sealing stopper and hollow needle

A convenience of the use of a pre-evacuated or evacuable container witha self-sealing stopper of rubber or a similar material is that, when thestopper is penetrated by a needle, blood up to a predetermined volumecan flow into the container without any further action by the operatorother than to keep the channel for blood flow unobstructed. For a singlesample of blood this can minimise spillage and patient distress. Seee.g. what is possibly the first use of a self-sealing penetrable rubberstopper, Kleiner U.S. Pat. No. 2,460,641 ref. 15. A further referencethat may be mentioned, though not concerned with blood sampling, isChavarot Fr. 950 588 ref. 16.

b) Evacuated Container

Using a different means for sealing the evacuated container, theearliest patent is probably Brown U.S. Pat. No. 1,124,285 ref. 17,possibly the first pre-evacuated blood-taking vessel.

c) Allowing escape of gas

If non-evacuated containers with perforable seal are used (with needle)means must necessarily be provided for removing or allowing escape ofthe air or gas enclosed.

2) Means of controlling flow from a double-ended needle, or catheter,i.e. how to minimise blood spillage as several different containers arefilled in turn

Common practice at the present day, though not universal is to use adouble-ended needle of which the extra-corporeal end is shrouded with asoft rubber sheath resembling a condom in geometry, though not in size.The sheath is penetrated easily when the extra-corporeal needle-end isthrust the rubber stopper of an evacuated sample tube, but up to thattime has acted as a valve preventing premature escape of blood. When theneedle is withdrawn, the sheath re-seals at least in part, and thuslimits the spillage of blood as several different evacuated samplecontainers are attached in turn. Such means are only partly successfulin preventing spillage of blood. Such needle-sheaths tackle problems (i)and (iii) in an inexpensive manner, but with only partial success--andrunning through a series of sample containers at the bedside cannot becalled elegant. For illustrations (but not the original invention) seerefs. 1-3.

Other additional on-off valve systems are described in many patents, ofwhich examples are refs. 1, 2, 4-6.

Any on-off valve system should be helpful in limiting blood spillage,but these do not meet the requirement for simplicity (vii).

3) Simultaneous distribution of blood to several separate containers

Refs. 7-10 cover devices which attempt to solve problem (i) by allowingblood from a single venepuncture to flow along a system of channels toseveral containers in a manner which is, in principle totally enclosed.Thus blood spillage (iii) should be minimal, at least at thebedside--limited to the venepuncture itself. These devices arerelatively complex and costly, and there are difficulties of scale andof maintaining flow.

Chamber intermediate between blood source and collection container

Many patents provide for a preliminary chamber between theextracorporeal needle-end and the main blood collection chamber, or achamber within the double-ended needle system itself (e.g. refs. 5, 7,11-13). The objective vary. The most consistently cited objective is a"tell-tale" to allow the operator to confirm that the venepunctureneedle is in place by the appearance of blood in this "tell-talechamber", for example Percarpio U.S. Pat. No. 4,155,350 ref. 13.

Here the stopper of an evacuated collection container is itselfhollow--and made of translucent material so that its contents can beseen. Advantages cited are that the angle of the needle to the vein isvariable and flexible, and blood can be seen to enter the hollowstopper, confirming that the venepuncture needle has reached its targetand is within a blood-filled space. However there is no suggestion thatthe stopper is used to collect a sample; it is not for example evacuatedand contains no materials such as anticoagulants.

McDonald U.S. Pat. No. 3,937,213 ref. 14 describes what is more a systemor kit of units than a single device. Blood is collected from anintravenous needle and flexible tube into a first evacuated container.Then in a second operation, with or without prior centrifugation toseparate cells from plasma or serum, blood or the liquid portion ofblood is transferred (again via needles and flexible tubes) into asecond evacuated chamber, within which are individual sample tubes whichcan be filled in turn or the sample tubes are each individuallyevacuated. There are many subsidiary features to the system. Althoughthe system fulfils several of the intended functions of the presentinvention, the concept of filling chambers in turn by passing one needlesuccessively through outer and one or more inner dividing closures isnot present. There are objections too on the basis of complexity, fiddlyoperation, risk of contamination of laboratory personnel,mis-identification of samples, etc.

Worrall U.S. Pat. No. 3,382,865 applies two or more separate containersto a fixed needle but he does not appreciate the problems ofcontamination, or confusion of samples, nor that of exposure of thesampling needle to atmospheric pressure, as appears from the very factthat he shows successive containers applied to a fixed needle.

    ______________________________________    References    ______________________________________    1.     Ritter          DE 3 740 269    2.     Wanderer        US 4 731 059    3.     Zanotti         US 5 084 034    4.     Russo           US 3 494 352    5.     Abramson        US 4 166 450    6.     Christinger     US 4 441 951    7.     Cinqualbre      US 3 405 706    8.     Horn            US 3 494 351    9.     Sausse          US 3 696 806    10.    Cinqualbre      US 3 848 581    11.    Kaufman         US 4 340 068    12.    Percarpio       US 4 886 072    13.    Percarpio       US 4 155 350    14.    McDonald        US 3 937 213    15.    Kleiner         US 2 460 641    16.    Shavarot        FR  950 588    17.    Brown           US 1 124 285    18.    Becton, Dickinson                           AU  627 387    19.    Terumo K. K.    JP 62-51238 (63-216542)    20.    Worrall         US 3 382 865    ______________________________________

PRINCIPLES OF THE INVENTION

Important features of the invention are set out in the claims but arealso discussed generally below.

Most broadly the invention lies in a container for taking samples ofblood or other fluid, having tow or more sample chambers, so disposedthat a hollow needle, in communication with a source of the fluid canfill them individually in succession for separate subsequent use,characterised in that the chambers have perforable, self sealingdiaphragm or other closures and are so disposed and pre-evacuated, thatfilling can be conducted without withdrawal of the needle from aninitially pierced closure that separates the chambers or the first ofthem from the exterior, and without exposure of the needle to anon-evacuated space while in communication with the source of thesample, and in that the chambers can be separated from each other afterfilling.

The device thus consists of a number of chambers for receiving blood orother fluid, which are separated from each other and from theenvironment by perforable, self-sealing diaphragms, stoppers or likeclosures. The chambers are so arranged that a hollow needle which is incommunication with a source of blood or other fluid can be passedthrough an outer closure and then through one or more inner closures,each chamber being filled in turn. Most simply, the chambers andclosures form a linear sequence so that the needle passes through eachpreceding chamber on its way to the next--filling them on advance orwithdrawal. However where chambers are not linearly successive an outerdiaphragm is pierced then, without withdrawal, the diaphragms ofsuccessive chambers below are pierced by relative movement of needle,chambers or both. The linearly successive chambers are simplest toprovide and use. Chambers in parallel may however have advantages,particularly in provision of all chambers with a rounded end integralwith the main body of the chamber and more resistant to centrifugationthan designs in which lower end of the tube is closed with anelastomeric plug.

The connections between chambers, in the assembled device, are requiredto be gas-tight. For cheap disposable devices to be manufactured inplastics, or glass, suitable connection is for example by means ofelastomeric plugs, or screw threads, or a sealing wrap, or by continuityof the matrix across the join. For separation, glass for example canreadily be induced to crack along predetermined lines, as in ampoules ofinjection drugs, or a sealing wrap can be cut with a knife.

Generally, separation of the chambers after filling with sample can beby unscrewing, by disconnecting a joint relying on an elastomeric plug,or by cutting (whether through the matrix of the material which formsthe chambers, a plug which forms the junction, or a sealing wrap),though there is no limitation to any particular method.

After filling, the chambers are separated from each other and thecontents of each are available to be used for different purposes,despatched to different destinations, etc. Preferably, the chambersshould be joined together in such a way that after separation from eachother they cannot be re-united, or alternatively that it will be obviousupon inspection that such separation has previously occurred. This isautomatic when to separate the chambers the closures are sliced throughwithin their thickness, separating the chambers but leaving them sealed,but for example a sealing wrap also gives a tamper-evident assembly veryconveniently.

During manufacture, arrangements are made to place within each chamber asuitable additive (or no additive) so that the blood or other fluid issuitably prepared for whatever purpose is intended. The chambers of onedevice may contain different additives or the same additive, and maydiffer in volume.

Preferably also, during manufacture, all the chambers of each device aremarked in a permanent and preferably machine readable way to indicatethat they belong to one set.

BRIEF DESCRIPTION OF THE DRAWING

In the detailed description that follows, reference may be made to thedrawing comprised of the following figures:

FIG. 1 is a cross sectional view of the first embodiment of theinvention;

FIG. 2A is a partial cross sectional elevation depicting an element of asecond embodiment of the invention;

FIG. 2B comprises a partial cross sectional elevation of elements ofFIG. 2A in combination to form the container of the invention;

FIG. 3A is an isometric view of another embodiment of the invention;

FIG. 3B is a cross sectional elevation depicting the container of FIG.3A;

FIG. 3C is a cross sectional elevation of an element of the container ofFIG. 3B;

FIG. 4A is a partial cross sectional view of a connection assembly forconnecting adjacent chambers of the container of the invention;

FIG. 4B is an elevation view of another alternative connection assemblyfor connecting chambers or elements forming the container of theinvention; and

FIG. 4C is an elevation view of yet another embodiment of the connectionbetween adjacent chambers or elements forming the container of theinvention.

DETAILED DESCRIPTION

FIGS. 1-4, enlarged and not to scale in detail, illustrate alternativeembodiments of the invention but these are not necessarily the onlypossibilities. Different aspects of the use of the invention are shownin the various figures, and it is to be understood that aspects notshown in a particular figure may be applicable to that embodiment.

FIG. 1 shows an embodiment in which the first chamber (1) to bepenetrated by the needle (2) is attached to or forms part of the stopper(3) of a larger sample container (4), and would be separated from thatcontainer by the act of removing the stopper (3). Only two chambers (orspaces) are shown, but additional spaces could be provided by way of aconstruction resembling that in FIG. 2 or otherwise. As drawn, theneedle (2) is shown penetrating through the first chamber (1) and aself-sealing membrane (5) into the second chamber (4), into which it isdelivering blood (6), having already partially filled the first chamber(7): both chambers had been fully or partially evacuated before use. Theneedle (2) shown either forms part of a double-ended needle system or isattached to a syringe or an indwelling catheter.

FIGS. 2A and 2B show an embodiment in which a series of units (8) screwinto each other to form a stack (15), which may in principle be of anynumber of units, and the individual units may differ in length. Asdrawn, the lower unit (9) has a rounded, closed end (10) so that it canbe used as a centrifuge tube, usually but not necessarily afterseparating from the other units. As drawn, the upper unit is sealed atthe top end by a stopper (11) of rubber-like material, but an empty unitor adapted (short) unit can also serve for this purpose. For use as aseries of evacuated units, the screw fitting (12) must be so designedand made as to hold the vacuum, or for example a sealing wrap asdiscussed below used It is also possible to fuse the lower to the upperunit at one or more points around the circumference of each join suchthat the units concerned cannot be unscrewed and thus separated fromeach other without breaking the fused portions. As shown in FIG. 2A, ifreassembled, it is then visible to inspection that the fused portion hasalready been broken and therefore that the units have been dis-assembledat some earlier time.

FIG. 3A shows an embodiment in which the chambers each consist of alength of tubing (1) usually of clear or translucent rigid plastic, withopen ends which are sealed and enclosed by a double-sided elastomericplug (14). In this embodiment, the device consists of a stack (15) ofsuch chambers which are divided from each other after filling by cuttingthrough each of the intermediate elastomeric plugs (14) in such a waythat the integrity as a plug is maintained on both sides of the cut(16), as shown in FIGS. 3B and 3C. As drawn, the plug has ridges (17) todefine the point of cut, but this is not an essential features. Asdrawn, the lower chamber (18) is of larger volume than the others and isdesigned to be subjected to centrifugation using the lower elastomericplug (19) as a base. Neither of these however is an essential feature.In particular, the lower chamber may be constructed with an integral,rounded, rigid, plastic base such as is illustrated in FIG. 2 (10), andthis is preferred at higher centrifugal forces to obviate the risk ofleakage.

The detailed additional drawings of FIG. 4 show an elastomeric wrap (20)that in FIG. 4a may be used with the screwed assembly of FIG. 2 or inFIG. 4b in an assembly where the wrap alone secures units in the series.Such wraps conveniently provide both sealing, and a tamper-evidentconstruction, in that the wrap is destroyed on removal, or at least cut,to separate the units. FIG. 4c shows a further method of assemblingunits where a sealed-in pierceable membrane (21) like that in FIG. 2 isused but there is a separate elastomeric assembly plug (22)corresponding in that respect to the plugs (14) of the units of FIG. 3.

Method of Use

As to filling with blood or other liquid, the method of use in all theseembodiments is the same.

If a syringe is used, it is first filled with blood and the needle (2)is then thrust down through the stopper (3) and blood allowed to runinto the first chamber (1). When it is full, or sufficiently full, orpressures have equalised, the needle is thrust further through diaphragm(5) into the lower chamber (4), and this in turn is allowed to fill. Theneedle is then withdrawn and the chambers are separated, in the case ofthe embodiment of FIG. 1 by removing the stopper (3), open chambers aresealed, as may be required for some chambers in the embodiments of FIGS.1 and 2, and the separated chambers despatched to their intendeddestinations.

alternatively, the needle may form part of a double-ended needle system.In that case, once the lower (most distant) chamber is appropriatelyfilled, the intravenous needle will be first withdrawn from the vein(unless special circumstances dictate otherwise) before theextracorporeal needle-end is withdrawn from the device.

Alternatively, the needle may be attached to an indwelling catheter. Inthis case, the first chamber would be for discard, as discussed above,and would be appropriately sized to ensure that all contaminants fromthe lumen of the catheter were flushed out by fresh blood flowing fromthe blood-vessel. When all chambers were filled, the flow of blood fromthe catheter would be arrested by a valve or other means beforewithdrawing the needle from this device.

I claim:
 1. A container for taking samples of blood or other fluid,having two or more sample chambers so disposed that a hollow needle, incommunication with a source of the fluid can fill them individually insuccession for separate subsequent use, characterized in that thechambers are pre-evacuated and have perforable, self sealing closurespositioned in combination with each of said chambers, said closuresincluding means whereby filling each separate chamber can be conductedwithout withdrawal of the needle from an initially pierced closure thatseparates the chambers or the first of them from the exterior, andwithout exposure of the needle to the exterior while in communicationwith the source of the sample and in that after filling the chambers bythe needle, the needle can be withdrawn to the exterior and the chamberscan be separated from each other.
 2. A container according to claim 1wherein the chambers are in a linear series separated by a correspondingseries of closures successively pierced by the needle.
 3. A containeraccording to claim 2 wherein the chambers are separable by cutting theor each separating closure, still sealed, across within its thickness.4. A container according to claim 1 wherein the chambers are united by asealing wrap or other tamper-evident means.
 5. A method of takingsamples of blood or other fluid wherein the chambers of a container asclaimed in claim 1 are filled with samples by use of the hollow needle,and are separated for subsequent analysis or test of the samples.
 6. Acontainer for taking samples of blood or other fluid comprising, incombination:an array of linear, successive sample chambers defining aunitary container, each of said chambers separated from an adjacentchamber by a single, self-sealing diaphragm, said unitary containercomprised of a rigid material forming the side walls of each chamber andsaid diaphragm forming at least one end wall of each chamber, saiddiaphragms axially aligned with one another for receipt of a hollowneedle piercing therethrough sequentially upon advance or withdrawal ofsaid needle into the chambers, said chamber side walls being connectedtogether to form the unitary container by a releasable connectionelement joining the side walls together, said needle connectable to eachof said chambers without intervening exposure thereof to the exterior ofthe container.
 7. The container of claim 6 wherein the connectionelement comprises a threaded connection of the side walls.
 8. Thecontainer of claim 6 wherein the connection element comprises a singlesealing member capable of being severed to thereby separate adjacentchambers.
 9. The container of claim 6 wherein the connection elementincludes a wrap seal joining the rigid side walls.
 10. The container ofclaim 6 wherein at least one of the chambers is at least partiallypre-evacuated.
 11. A method of taking samples of blood or other fluidwherein the chambers of the container as in claim 6 are filled withsamples by use of a hollow needle, and are separated fro subsequentanalysis or test of the samples.